Fluid jet size measuring device



Jan. 15, 1957 R. P. PRICE 2,777,321

FLUID JET sxza MEASURING DEVICE Filed Sept. 29, 19s;

1/ l I 11omosYf Qichqrd K). I DV'LCQ W W United States Patent 2,177,321FLUID JET SIZE MEASURING DEVICE Richard P. Price, Cleveland, Ohio,assignor to Barnes Drill (30., Rockford, 11]., a corporation of IllinoisApplication September 29, 1953, Serial No. 382,957

3 Claims. (Cl. 73--37.9)

This invention relates to a device for measuring the size of a worksurface, particularly a cylindrical surface through the use of aplurality of fluid jets directed against the work surface from nozzleson a carrier supported for free transaxial floating under the influenceof reactionary forces produced by the jets and tending to center thecarrier relative to its support.

One object is to shape the nozzle outlets in a device of the abovecharacter in a novel manner such as to improve the usable measuringrange of the device and also increase the magnitude of the forcestending to center the nozzle carrier. I

The invention also resides in the novel shaping of the nozzle orificesto minimize vibration of the nozzle carrier so as to provide optimummeasuring sensitivity.

Other objects and advantages of the invention will become apparent fromthe following detailed description taken in connection with theaccompanying drawings, in which:

Figure 1 is a transverse sectional view taken along the line 1-1 of Fig.2 and showing the improved sizing device as incorporated in a honingtool.

Fig. 2 is a fragmentary sectional view taken along the broken line 22 ofFig. 1.

Fig. 3 is a section taken along the line 3-3 of Fig. 2.

Fig. 4 is a face view of one of the nozzles.

While the improved sizing device is usable in measuring various types ofwork surfaces, it is especially adapted for use in measuring theinternal diameter of a work bore when mounted on the body 11 of the toolsuch as a hone. In the conventional form shown, the hone comprises aplurality of abrasive sticks 12 guided for radial adjustment relative tothe body 11 and adapted to be expanded by cams 13 while the tool andsizing device are rotated and reciprocated back and forth within thebore during finishing of the bore wall.

In this environment, the gaging device may be utilized to indicatecontinuously the diameter of the bore being honed and to give a signalwhen a predetermined size has been attained. It includes generally aplurality of orifices 1 supplied with pressure fluid through a commonflexible conduit 15 and floatingly mounted on the body 11 in position todirect jets of fluid against the wall of the bore thereby causing thepressure in the conduit to change as the gaps 16 between the orificesand the work surface are changed by the action of the honing stones 12.

Each orifice 14 comprises an enlarged recess or expansion cavity 14 atthe end of a restricted passage 14 defined by a tubular plug 17 pressedinto a radial lug 18 which projects from the periphery of a carrier ring19 between two of the honing stones. Herein, the ring is disposedbetween and slidably guided by walls 20 of a groove 21 which encirclesthe body 11 intermediate the ends of the stones. The carrier ring isthus adapted for free bodily floating radially of the tool body 11 andits longitudinal rotational axis but is held against turning relative tothe body by a pin 22 projecting from the body into a radial slot 23 inthe carrier.

At their inner ends, the restricted nozzle passages 14 communicatethrough holes 24 with an annular passage 25 connected to the lower endof the flexible conduit 15. The outer ends of the nozzle tubes areenlarged to form pads 26 secured to the carrier ring 19 as by screws 27and each having an outer surface 28 which surrounds the orifice openingand conforms closely to the contour of the work surface 10 beingmeasured. The pads are mounted on the carrier ring 19 so as to providevery narrow gaps 16 between the bore wall and the pad faces, these gapspreferably being on the order of .005. of an inch although their widthmaybe increased to about 0.10 without substantial reduction of thecentering action 'described later.

Liquid delivered under pressure, for example 40 p. s. i., through theconduit 15 flows outwardly through the-passages 14 and the cavities 14and is directed in the form of jets against the bore wall. The liquidthen escapes in the form of a thin sheet through the gaps 16, thecombined rate of flow being proportional to the sum of the widths of thegaps so that the value'ofthe back pressure in the conduit 15 is ameasure of the diameter of the bore. Suitable means such as a pressureswitch well known in the art may be employed to sense such pressurechanges and therefore measure the bore size continuously while the boreis being honed.

Along with this size measuring function, the orifices 14 and the fluidjets defined thereby may, when the orifices are enlarged at their outerends as described above, perform the additional function of derivingforces which act on the floating ring 19- and are combined in aresultant force that urges the ring transaxially toward a positioncentered relative to the bore, the gaps 16 then being of equal width sothat the pressure in the supply line will correspond more accurately tothe diameter of the bore. Such centering action is due to the fact thatwith a constant pressure supplied to all of the orifices and with thefloating ring off-center, the pressure in the cavity opposite thenarrowest gap will be greater than the pressure in a cavity of a widergap. Thus the pressure differential is in a direction to urge the ringtoward centered position and maintain the gaps of uniform width I havediscovered that the centering action above described as well as theover-all measuring sensitivity of the device may be increasedappreciably by shaping the walls defining the fluid orifices so thatthere is a smoother flow and gradual spreading out of the liquid inpassing into and out of each expansion cavity M This is achieved inaccordance with the present invention by flaring the walls of the cavitygradually and outwardly thereby avoiding sharp corners or reentrantrecesses that would otherwise interfere with the free and direct flow ofthe liquid within the nozzle and also through the gaps 16.

In the present instance, the desiredflaring of the cavities 14* may beachieved by a simple countersinking operation to cone the cavity Wall atan included angle of about 60 degrees. The frusto conical wall thusformed intersects the pad face 28 at a diameter of /8 of an inch, isabout A of an inch deep, and intersects the A3 inch restricted passage14* at a very blunt edge 30. The liquid flows around the latter withoutappreciable disturbance and escapes through the gap 16 around theorifice base in a sheet of gradually decreasing thicknesse.

With the orifices thus shaped, it has been found in practice that thetransaxially directed centering forces acting on the floating carrier 19are of substantial magnitude and effectually maintain the carrier incentered position even when the tool, which may be of substantialweight, is mounted to turn about a horizontal axis. At the same time andapparently because of the more uniform flows of liquid through and fromthe different orifices, the overall sensitivity of the measuring deviceas well as its range of precise operation have been increasedconsiderably as compared to prior construction.

I claim as my invention:

1. In a jetsizing device for measuring the diameter of a cylinder, thecombination of, a support adapted to extend along the cylinder axis, acarrier mounted on said support for lateral floating transaxially of thecylinder, means on said carrier defining a plurality of orificesangularly spaced apart and opening radially toward said cylinder, andmeans defining a fluid supply chamber on said carrier communicating witheach of said orifices, each of said orifices having a passage radiallyspaced from the periphery of the carrier and an expansion cavity definedby a wall diverging at an-angle of about sixty degrees from the endofsaid passage to an enlarged opening at said carrier periphery.

2. In a jet sizing device for measuring the diameter of a cylinder, thecombination of, a support adapted to extend along the cylinder axis, acarrier mounted on said support for lateral floating transaxially of thecylinder, means on said carrier defining a plurality of orificesangularly spaced apart and opening radially toward said cylinder, andmeans defining a fluid supply chamber on said carrier communicating witheach of said orifices, each of said orifices having a restrictionradially spaced from the periphery of the carrier and an expansioncavity defined by a wall diverging from said restriction to an enlargedopening at said carrier periphery.

3. In a jet sizing device for measuring the diameter of a cylinder, thecombination of, a support adapted to extend along the cylinder axis, acarrier mounted on said support for lateral floating transaxially of thecylinder, means on said carrier defining a plurality of orificesangularly spaced apart and opening radially toward said cylinder todischarge jets of fluid against the latter, and means on said carriercommunicating with each of said orifices to supply fluid under pressurethereto and form said jets, each of saidaorifices having a restrictedpassage and an expansion cavity gradually flaring therefrom to the openend of the orifice whereby to provide for a smooth continuous flow ofthe fluid through said cavity and then across the cylinder surface.

References Cited in the file of this patent UNITED STATES PATENTS1,946,924 Allen et al. Feb. 13, 1934 2,125,445 Holveck Aug. 2, 19382,254,259 Aller Sept. 2, 1941 2,325,008 Gruett July 20, 1943 2,446,071Aller July 27, 1948 2,538,785 Karig Jan. 23, 1951

